The use of solid hydridable materials to store hydrogen is disclosed in numerous patents, such as, for example, U.S. Pat. Nos. 3,508,514, 3,516,263 and 4,036,944. These solid hydridable materials are characterized by an interrelation of temperature, pressure and hydrogen content, such that, at any given temperature, the hydrogen content of the hydridable material is determined by the partial pressure of the hydrogen in contact with that material. Generally, as temperature rises it takes a greater partial pressure of hydrogen to maintain a given concentration of hydrogen in the hydridable material. The converse is true as temperature decreases. As hydrogen combines with the hydridable material, heat is given off, i.e., the reaction is exothermic. Conversely, when hydrogen is released from hydridable material it absorbs heat and the reaction is endothermic. The aforestated facts are the reasons why in storing hydrogen or combining and releasing hydrogen from hydridable material, it is most necessary that good heat transfer means be provided between the actual site of the hydriding or dehydriding reaction and the walls of a container. In addition, in order that the hydriding or dehydriding reaction takes place, it is necessary to provide gas paths which extend throughout the mass of hydridable material.